Glitch?
So i've been seeing this happen for a while with my own heat buster, but i couldn't narrow down the cause. This mainly happens with Grumbils with me, when i launch heat buster and if the animation is interrupted after the attack, by say grumbil #2 attacking me.. I get to attack again with Heat Buster. Im not sure if its a glitch or it is part of how Heat Buster works.
*Recommendation to Heat Busters* Use a Tower Cylinder with heat buster on bosses or huge rooms with strong mobs; (Hard Mode Shadow warrior tends to take 1.8-2.3k base damage w/o crit and w/ Heat buster title) However the stamina drain is annoying, as its about 2x the normal stamina drain (23 Stamina becomes 46)
**Carry alot of Stamina Potions when using Heat Buster; that goes for if your using Chain Cylinder too, and both at the same time hurts stamina quite a bit.